Sunglasses are made in different materials such as acetate sunglasses, injection sunglasses and metal sunglasses. Sunglasses come in many styles, shapes, colors and brands. There are polarized, prescription, clip-on, flexible, men's, women's, unisex, children glasses, designer, and custom-made sunglasses. There are police, pilot and rescue sunglasses, biker, skier and other sports sunglasses. There are even sunglasses with built-in audio digital players.